Incandescent electric lamp cooling means



FIP-3004 XP 2,048,214 UYSS HGTGTGC SeafCh ROO.' #0

July 21, 1935- A. s. HOWELL Er AL 2,048,214

INCANDESCENT ELECTRIC LAMP COOLING MEANS Filed July 23, 1934 Patented July 21, 1936 UNI-TED STATES PATENT OFFICE INCANDESCENT ELECTRIC LAMP COOLING MEANS Albert S. Howell and Bruno Stechbart, Chicago, Ill., assignors to The Bell & Howell Company, Chicago, IIL, a. corporation of Illinois Application July 23, 1934, Serial No. 736,465

T Claims.

providing for the cooling or! incandeent electric lamps of theconcentrated filament type, sach as are used in picture projecting machines, with a view toward maintaining the lamps at a sate and 1g.. practical temperature and preventing immature burning out thereof,

- With this object in viewE our invention consists incertain features of! novelty lx1-.the constmctiolx, combination, and. arrangement oi'. parts by which the said object and certain other objects hereinafter appearing are eiected, all as fully described with reference to the accompanying drawing and more` particularly pointed out in the appended claims.

- In the said drawing- -'1ligure 1 is a central vertical section of the lampy house of a motion picture projecting machine embodying our invention; and

Figurezlis a. perspective view of the air cinrent tube of'our invention, hereinafter described.

Referring to the drawing, I designates. a verticallyidisposed generally circular lamp chamber having itsllowerend connected with an air conduit 2 and provided at its upper end with a removable top 3 provided with holes 4 for the passage of an air current upwardly therethrough, the air current being effected by a suitable fan, not shown, forcing air into the conduit 2 and upwardly through the lamp chamber as is usual on motion picture projecting machines.

Disposed centrally within the bottom portion oi the lamp chamber is a lamp socket structure, generally designated at 5, and mounted in the socket 5 is a cylindrical incandescent electric lamp 6 of the concentrated filament type, the concentrated lament being indicated at 1, the lamp being thus located centrally in the lamp chamber and in vertical position, as is usual.

The cylindrical wall of the lamp chamber is provided with diametrically opposite openings 8 alined with the filament 1, and a focusing reflector 9 is mounted in one of these openings and a condensing lens II is mounted in the other of these openings, the reflector lamp lament and condensing lens being alined and cooperating to provide a projection light.

Disposed within the lamp chamber, is a tubular heat shield I2 surrounding the lamp B adapted for the passage of air on the exterior and interior thereof, this shield serving to prevent the (Cl. 24o-47) chamber wall from becoming excessively hot and being provided with diametrically opposite openings I3 in the region ci the lamp lament I for the accommodation ot the reector 9 andy con-- densing lens Hr Also disposed within the lamp chamber, is a transparent tubular member i4, constructed of heat resistant material such as glass capable of withstanding relatively high temperatures, and

this member is arranged within the heat shield. 10i

I2 and surrounds the lamp 6 and is adapted for'` the passage ofv einen the exterior and interior:V thereof, there. heini-.Summit dierence between; the diameters off-the shieldV I 2 the member kIk and thelamp for thispurpose.

The endrportlons of the tubular member Il are oi a relatively large diameter, see Figures l ands 2whi1ethe intermediate portbnthereof in the region of the filament 'l of the lamp is reduced in diameter as designated at Ii, the reducedportion beingpreferably cylindrical as shown and being disposed opposite the filament I of the! lamp for they undiitorted passage; 0f the light therethrough.

Theheat shield I2 and the member I4 are sup- 25 ported. at their lower ends in concentric relation with each other and. with the lamp chamber and lamp by vmeans of shouldered lugs t6 formed. on the lamp chamber wall, and the lower end of the member Il is preferably flared outwardly, as designated at Il, to increase the air current between the member Il and the lamp 6'.

In operation a current of air is forced upwardly through the lamp chamber from the conduit 2 by-a suitable fan as aforesaid, and the air passes between the lamp chamber wall and the shield I2, between the shield I2 and the member I4, and the lamp, serves to carry off the heat dissipatedby1 the energized filament 1 of the lamp.

lThe reduced intermediate portion I5 of the member I4 has a Venturi be eect and being disposed in the re o t e filament increases the velocity of the air current on the lamp in this region and thus increases the carrying off of the heat of the nlament.'

It will be observed that by reason of member I4 being transparent, at least in the region of the filament, the passage of the light is not interfered with and that the member Il has no transverse openings which would interfere with the Venturi tube eiiect at the filament or hottest part of the lamp.

While we have described and shown the pre- I ferred embodiment of our invention we do not wish to be limited to the precise details of construction as changes may readily be made without departing from the spirit of our invention, but

having thus described our invention, we claim as new and desire to secure by Letters Patent the 5 following:

1. In a device of the character described the combination with a lamp chamber adapted to have an incandescent electric lamp of the concentrated filament type located therein and to have an air current pass therethrough, of a tubular member located in said lamp chamber for the passage of an air current therethrough and surrounding said lamp and provided with a portion of reduced diameter disposed in the region of the filament of said lamp, at least a portion of said tubular member being of transparent heat resistant material for the passage of light from said lament transversely of said tubular member.

2. In a device of the character describedthe combination with a lamp chamber adapted to have an incandescent electric lamp of the concentrated lament type located therein and to have an air current pass therethrough, of a heat.

.resisnagiht transparent tubular member located in said lamp chamber for the passage of an air cur@ rent therethrough and surrounding said lamp and provided with a portion of reduced diameter disposed in the region of the filament of the lamp'.

3. In a device of the character described the combination with a lamp chamber adapted to have an incandescent electric lamp of the concentrated lament type located therein and to have an air current pass therethrough, of a heat resistant transparent tubular member located in said lamp chamber for the passage oi an air current therethrough and surrounding said lamp and having its intermediate portion reduced in diameter and disposed in the region of the filament of the lamp.

4:35 4. In a device of the character described the combination with a lamp chamber adapted to have a cylindrical incandescent lamp of the concentrated iilament type located centrally therein in a vertical position and adapted to have an air 152 current pass vertically therethrough, of a tubular member located in vertical position in said chamber and surrounding said lamp and provided with a portion of reduced diameter disposed in the region of the lament of the lamp, at least a portion of said tubular member being of transparent heat resistant material for the passage of light from said filament transversely or said tubular member.

5. In a device of the character described the 5 combination with a lamp chamber adapted to have a cylindrical incandescent electric lamp of the concentrated iilament type located centrally therein in a vertical position and adapted to have an air current pass vertically therethrough; of a. 10 transparent heat resistant tubular member located in vertical position in said chamber and surrounding said lamp and provided with an intermediate portion of reduced diameter disposed in the region of the filament of the lamp. 15

6. In a device o! the character described the combination with a lamp chamber adapted to have a cylindrical incandescent electric lamp of the concentrated lament type located centrally therein in vertical position and adapted to have 20 an air current pass vertically therethrough, ot a transparent heat resistant tubular member located in Vertical position in said chamber and surrounding said lamp and provided with an intermediate portion of reduced diameter disposed 25 in the region of the iilament of the lamp, said reduced portion including a cylindrical tubular formation opposite said filament.

7. In a device of the character described the combination with a lamp chamber adapted to am have an incandescent electric lamp of the concentrated filament type located -thereinv and to have `an air current pass therethrough, of a tu. bular'heat shield located in said lamp chamber and surrounding said lamp and provided with 356 diametrically opposite openingsin the region of the filament of the lamp and adapted for the passage of an air current on the exterior and interior thereof, and a transparent heat resistant tubular member located in said lamp chamber and arranged within said heat shield and surrounding said lamp and adapted for the passage oi' an air current on the exterior and interior thereof and having its intermediate portion reduced in diameter and disposed in the region of the iilai ment of the lamp.

ALBERT S. HOWELL. BRUNO STECI-IBART. 

